Details

Autor(en) / Beteiligte

• Park, Jung H.
• Kim, Min G.
• Jang, Hyun M.
• Ryu, Sangwoo
• Kim, Young M.

Titel

Co-metal clustering as the origin of ferromagnetism in Co-doped ZnO thin films

Ist Teil von

• Applied physics letters, 2004-02, Vol.84 (8), p.1338-1340

Erscheinungsjahr

2004

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The origin of ferromagnetism in ZnO-based systems was investigated using Co-doped ZnO thin films as prototypical examples of II–VI-based diluted magnetic semiconductors. In spite of the atomic-scale dissolution of Co ions in wurtzite ZnO, both the magnetization-temperature curve and the magnetization-field curve demonstrated that Zn1−xCoxO thin films were paramagnetic for x⩽0.12. On the other hand, Zn1−xCoxO films with x greater than 0.12 were characterized by the Co-metal clustering and apparently showed room-temperature ferromagnetism. The discrepancy between the zero-field cooling and the field cooling curves further indicates that Co-doped ZnO films (for x>0.12) are superparamagnetic and the observed ferromagnetism originates from the nanometer-sized Co clusters.